Sid's Onion Burger

"For these addictively tasty burgers, ground beef is pressed onto the griddle with paper-thin slices of onion and seared until crisp around the edges. The recipe comes from Sid's Diner, a restaurant in El Reno, Oklahoma." Courtesy of Saveur Magazine.

• Ready In: 2 mins
• Serves: 6

Ingredients

• 4  tablespoons canola oil
• 1  lb ground beef (gently formed into 6 balls)
• 2  medium yellow onions (very thinly sliced with a mandoline or a sharp knife and divided into 6 equal portions)
•  kosher salt, to taste
• 6  slices American cheese
• 6  hamburger buns, toasted

Directions

1. Working in 2 batches, heat 2 tablespoons oil in a 12" cast-iron skillet over medium-high heat.
2. Add 3 beef balls and, using the back of a spatula, press down on them until they're thin; cook for 1 minute.
3. Top each patty with a portion of the onions; season with salt.
4. Press onions into the meat and cook for 1 minute more.
5. Flip burgers; flatten with the spatula. Place a cheese slice on each patty and let melt while onions and meat brown.
6. Serve on buns.